This is a highly readable little book, and I recommend it, with a few caveats. Sobel presents her material logically and lucidly. She is a good prose stylist and is obviously an accomplished reporter. This book, however, feels like what it is: a series of articles stretched out a little to accommodate a best-seller format. The story is an intriguing one. An 18th century inventor rises from obscurity and against great odds and bias, produces an instrument that will prove of enormous benefit to his country and to humankind. Just don't go into the reading of this book expecting great historical writing. Sobel acknowledges in a postscript that she doesn't include footnotes "because this book is intended as a popular account, not a scholarly study...". She has culled her research, for the most part, from interviewing historians, attending a seminar, and visiting various sites in England. At least she is forthright about her methodology, so she won't have to face the gauntlet that Kearns-Goodwin and Ambrose have recently had to run (mixed metaphor?). Another minor irritation arises from the fact that one of the prominent blurbs one finds when opening the book comes from Diane Ackerman, whom Sobel later identifies in her list of acknowledgments as her "dear friend." Again, at least she's being transparent about it, but it still strikes me as a bit disingenuous. To her credit, Sobel does include a rather comprehensive bibliography, so those who want to further investigate Harrison's achievement are well guided. Longitude is a good, quick summer read. For those who want some pith with their punch, however, I would recommend the A&E Sturridge video or CD adapted from this work.